<template>
    <el-container class="home-container">
        <!-- 头部区 -->
        <el-header> 
            <div >
                <img src="../assets/heima.png" alt="">
                <span>电商后台管理系统</span>
            </div>
            <el-button type="info" @click="logout">退出</el-button>
        </el-header>
         <!-- 页面主体区 -->
        <el-container>
           <!-- 侧边栏 -->
            <el-aside :width="isCollapse ? '64px':'200px'">
                <!-- 侧边栏 菜单区域 -->
                <div class="toggle-button" @click="toggleCollapse">|||</div>
                <el-menu :default-active="activePath" class="el-menu-vertical-demo" background-color="#333744" text-color="#fff" active-text-color="#409EFF" :unique-opened="true" :router="true"  
                :collapse="isCollapse" :collapse-transition="false"   >
                <!--:router="true" 左侧菜单栏改造为路由链接  -->
                     <!-- 一级菜单 -->
                    <el-submenu :index="item.id+''" v-for="item in menulist" :key="item.id">
                       <!-- 一级菜单的区域 -->
                        <template slot="title">
                            <!-- 图标 -->
                            <i :class="iconsObj[item.id]"></i>
                            <span>{{item.authName}}</span>
                        </template>
                            <!-- 二级菜单 --> 
                            <el-menu-item :index="'/'+subItem.path+''" v-for="subItem in item.children" :key="subItem.id " @click = "saveNavState('/'+subItem.path)">
                                <template slot="title">
                                    <!-- 图标 -->
                                    <i class="el-icon-menu"></i>
                                    <span>{{subItem.authName}}</span>
                                </template>
                            </el-menu-item>    
                    </el-submenu>
                </el-menu>
        </el-aside>
            <!-- 右侧内容 -->
            <el-main> 
                <!-- 路由占位符 会把该地址 对应的组件 显示到这个位置-->
                <router-view/>
            </el-main>
        </el-container>
    </el-container>
</template>

<script>
export default {
    data(){
        return{
              // 左侧菜单数据
        isCollapse:false
        ,menulist:[],
        // 被激活的链接地址
        activePath:'',
        // 分别对应
        iconsObj:{
            '125':'iconfont icon-user',
            '103':'iconfont icon-tijikongjian',
            '101':'iconfont icon-shangpin' ,
            '102':'iconfont icon-danju',
            '145':'iconfont icon-baobiao',
        }
        }
    }
    ,created(){
        this.getMenuList();
        this.activePath = window.sessionStorage.getItem('activePath')
    },
     methods:{
         logout(){
            //  清空sessionStorage
            window.sessionStorage.clear()
            this.$router.push('/login')
        },
        // 获取所有的菜单栏
       async getMenuList(){
           const {data :res}= await this.$http.get('menus')
           if(res.meta.status !==200) return this.$message.error(res.meta.msg)
           this.menulist = res.data
           console.log(res)
        },
        // 点击按钮 切换菜单的折叠和展开
        toggleCollapse(){
            this.isCollapse =!this.isCollapse
        },
        // 保存链接的激活状态
        saveNavState(activePath){
            window.sessionStorage.setItem('activePath',activePath)
            this.activePath =activePath
        }
     }
}
</script>
<style lang="less" scoped>
    .home-container{
        height: 100%;
    }
    .el-header{
        background-color: #373D41;
        display: flex;
        justify-content: space-between;
        padding-left: 0;
        align-items: center;
        color: #fff;
        font-size: 20px;
        > div{
            display: flex;
            align-items: center;
         span{
                margin-left: 15px;
            }    
        } 
    } 
    .el-aside{
        background-color:#333744;
        .el-menu{
            border-right: none;
        }
    }
    .el-main{
        background-color: #EAEDF1;
    }
    .iconfont{
        margin-right: 10px;
    }
    .toggle-button{
        background-color: #4A5064;
        text-align: center;
        font-size: 10px;
        line-height: 24px;
        color:#fff;
        letter-spacing: 0.2em; //每天线之间 有了一点距离
        cursor: pointer;
    }
</style>